Renovation project of phase ii major pumping station of jingtai chuan electric power irrigation administration in gansu province

一、Project background

Jingtai chuan electric power irrigation project is a high lift, large flow rate, multi-step electric water irrigation project. Located in the middle of gansu province, the eastern end of hexi corridor, 180km north of the provincial city of lanzhou; The irrigated areas are adjacent to the Yellow River and the north to the tengli desert. It is a large (2) electric power irrigation project across the Yellow River and shiyang river basin. The first phase of the whole project by electric scene, scene electrical phase ii project (second phase), phase ii of scene electric extension to the minqin water transfer project (hereinafter referred to as polls engineering) of three parts, one scene electric period is an independent water supply system, scene electric phase ii and minqin share a water system water transfer project. The whole scene electrical engineering design water flow of 28.56 cubic meters/second, increase the flow of 33 cubic meters per second, 43 construction of pumping station, installed capacity of 270 mw, the highest lift 713 m, design in the water volume of 475 million cubic meters. The construction of the dry, branch, and canal 1391, long 2422km. Irrigated area covers a total area of 1,496 square kilometers, the total land area is 197 million mu, the area of agriculture is 142.40 million mu, control irrigation area of 1 million mu. Irrigated area drought, less rain, more sand, belong to the dry continental climate; Both surface runoff and groundwater in the irrigation area are extremely deficient, and the irrigation water source is from the Yellow River.

二、Drainage problems

Main problems of pump station:

1、Early construction, long running time, low design standards and poor matching Settings；

2、Electromechanical equipment overage service, disease operation, aging serious, and many to eliminate the product, the energy consumption is high, the efficiency is low；

3、River sediment content is high and harmful, it not only causes silting and water intake difficulties, but also the abrasion of the pump is serious, the water pump overflows the service life is short, the running cost is high；

三、The solution

Through many communication with the site owner, design institute and China irrigation and drainage development center, anhui sanlian pump industry has provided a complete solution for the project owner.

1、Three-dimensional numerical simulation, flow analysis and hydraulic optimization of flow field in double suction pump

Through CFD numerical simulation of flow field inside the pump, the complex flow characteristics in the analysis of pump, accurate quickly find out the key problems in design of the double suction pump, and adopt numerical simulation "- modified flow channel geometry parameters and shape - numerical simulation of multiple cycle, the internal flow characteristics analysis method to solve the double suction pump, can achieve the efficient hydraulic model.

2、Wear resistance design

①、The design method with low speed and low package Angle is adopted, and the circumference velocity of the impeller outer diameter is controlled within 40m/s；

②、Reduce the diameter of the impeller and improve the wear at the mouth ring；

③、The gap seal of mouth ring and other gaps shall be protected by anti-wear measures, and the length of seal clearance shall increase appropriately；    

④、The pump body sealing ring outer circle sets two O ring to avoid the friction between the high and low pressure cavity of the pump case；

⑤、The impeller USES the blade alternate loading and v-shaped staggered form to reduce the wear of the impeller outlet part and the side of the volute。

3、Material selection of overcurrent parts

Water working condition of the main characteristic of complex, containing large amount of mud, run after a period of time, will cause the pump flow components wear serious, resulting in decreased pump efficiency significantly, the power consumption to increase, this requires the pump flow components of the material with good abrasion and erosion resistance。

Based on the analysis of the flow condition of the Yellow River, the material selection of the pump through the flow component is as follows：

①、Pump case: use of durable ductile iron QT500-7, and the thickness of the shell wall thickness to 40mm;

②、Impeller: double phase stainless steel DIN1.4460

③、Pump body seal ring: double phase stainless steel DIN1.4462

④、Sleeve: adopt 3Cr13 wear-resisting stainless steel and surface quenching treatment;

4、Anti-wear protection spraying technology

The pump shell is sprayed with polyurethane rubber coating to improve the scour ability of the pump shell.

四、The equipment parameters

五、Application effect

1、Compared with other manufacturers in China, efficiency is up about 2%；

2、The combined operation efficiency of the pumping station increased by about 8%, and the energy consumption was reduced by about 0.75 ~ 0.85 kWh/kt.

3、The cumulative service life of impeller and sealing ring of pump is greater than 12000h.